They were looking at exploding stars in the distant universe, and they noticed that not only is the universe expanding from its big bang origin, but its expansion is actually speeding up.

观察远处宇宙恒星爆炸的时候，他们注意到宇宙不仅从大爆炸起源点开始不断膨胀，膨胀的速度还越来越快。

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The clear inference is that the universe is expanding.

显然结论是宇宙在扩大。

《牛津词典》

Einstein's equations showed the universe to be expanding.

爱因斯坦的方程式表明宇宙正在扩大。

《柯林斯英汉双解大词典》

His investigation led to the most important astronomical discovery of the Twentieth century -- the expanding universe.

VOA: special.2009.04.29

Evidence that the universe is expanding was first discovered at Lowell Observatory by V.M.Slipher.

VOA: special.2010.07.11

Many of these observers will see their universe expanding.

ECONOMIST: The universe, it appears, may not be alone

In 1929 Edwin Hubble discovered that the Universe is expanding, which led to the Big Bang theory.

UNESCO: 2008 UK and Ireland Fellows

By 1932, however, there was observational data indicating that indeed the universe was expanding.

FORBES: Dark Energy Camera Could Reshape Einstein Cosmology